A Filter Unit for a Smoking Article

ABSTRACT

A filter unit for a smoking article includes a tube having a first portion and a second portion, wherein an inner diameter of the first portion is different from an inner diameter of the second portion. The filter unit also includes a sleeve at least partially surrounding the tube. Also described are a smoking article having the filter unit and a kit including a smoking article and the filter unit.

TECHNICAL FIELD

The present invention relates to a filter unit for a smoking article, asmoking article including such a filter unit and a kit of partscomprising a smoking article and a filter unit.

BACKGROUND

Cigarettes and other smoking articles produce an aerosol, such as smokein the case of cigarettes, which is inhaled by a user. A filter may beprovided as part of a smoking article, or can be provided as a separatecomponent which can be attached or coupled to a smoking article by auser. Filters can be configured to modify properties of aerosol producedby the smoking article; for example, by adding flavourant to the aerosolproduced by the smoking article.

SUMMARY

According to embodiments of the invention, there is provided a filterunit for a smoking article comprising a tube having a first portion anda second portion, wherein an inner diameter of the first portion isdifferent from an inner diameter of the second portion and a sleeve atleast partially surrounding the tube.

The second portion can be at a distal end of the filter unit.

The inner diameter of the second portion can be arranged to decreasewith distance from the distal end of the filter unit.

An inner diameter of the second portion can be greater than an innerdiameter of the first portion.

An outer diameter of the second portion can be greater than an outerdiameter of the first portion.

An outer diameter of the first portion can be substantially the same asan outer diameter of the second portion.

Each of the first portion and the second portion can have a first endand a second end, and the second end of the first portion can adjoin thefirst end of the second portion and can have an inner diametersubstantially the same as the first end of the second portion.

The tube can be formed from paper, card, cardboard or plastic.

The filter unit can comprise a cylindrical element, and the sleeve canat least partially surround the cylindrical element.

The cylindrical element can be formed from filter material and cancomprise a body having an end surface adjacent to the tube and a recessformed in the end surface.

The element can comprise a smoke modifying substance disposed within thefilter material of the element. The smoke modifying substance cancomprise an encapsulated substance.

The filter unit can be arranged to be coupled to a smoking article by auser.

According to embodiments of the invention, there is also provided asmoking article comprising a filter unit as set out above.

The second portion of the tube can be disposed at a mouth end of thesmoking article.

According to embodiments of the invention, there is also provided a kitcomprising a smoking article and a filter unit as set out above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1a is a side-on cross sectional view of a first filter unitincluding a tube formed from filter material and where the filter unitforms part of a smoking article;

FIG. 1b is a side-on cross sectional view of an outer chamfered tube foruse as an alternative to the tube used in the first filter unit of FIG.1 a;

FIG. 1c is a side-on cross sectional view of a filter insert for usewith the first filter unit of FIG. 1 a;

FIG. 2 is a side-on cross sectional view of a second filter unitincluding a tube formed from filter material and where the filter unitis provided as a discrete unit for use with a separate smoking article;

FIG. 3a is a side-on cross sectional view of a third filter unitincluding a filter body comprising a recess and where the third filterunit forms part of a smoking article;

FIG. 3b is an end-on view of the third filter unit of FIG. 3 a;

FIG. 3c is an end-on view of another third filter unit design having atriangular shaped recess;

FIG. 3d is an end-on view of another third filter unit design having ahexagonal shaped recess;

FIG. 4 is a side-on cross sectional view of a fourth filter unitincluding a tube formed from sheet material and provided as a discretecomponent for use with a separate smoking article;

FIGS. 5a to 5d are perspective views of an apparatus for shaping atobacco industry product;

FIGS. 6a to 6c are side-on cross sectional and end-on views ofrespective first, second and third shaping heads for use with theapparatus of FIGS. 5a to 5 d;

FIG. 7 is a flow diagram illustrating a method of shaping a tobaccoindustry product; and

FIG. 8 is a flow diagram illustrating a method of shaping a tobaccoindustry product.

DETAILED DESCRIPTION

As used herein, the term “tobacco industry product” is intended toinclude smoking articles comprising combustible smoking articles andtheir components such as cigarettes, cigarillos, cigars, tobacco forpipes or for roll-your-own cigarettes, (whether based on tobacco,tobacco derivatives, expanded tobacco, reconstituted tobacco, tobaccosubstitutes or other smokable material), electronic smoking articles andtheir components such as e-cigarettes, heating devices that releasecompounds from substrate materials without burning such as tobaccoheating products, and hybrid systems to generate aerosol from acombination of substrate materials, for example hybrid systemscontaining a liquid or gel or solid substrate; and aerosol-free nicotinedelivery articles and their components such as lozenges, gums, patches,articles comprising breathable powders and smokeless tobacco productssuch as snus and snuff. Components of the above articles include filterunits, filter plugs, filter inserts and tubes for use in products suchas smoking articles;

In one embodiment, the tobacco industry product is a smoking article forcombustion, selected from the group consisting of a cigarette, acigarillo and a cigar.

In one embodiment, the tobacco industry product is a non-combustiblesmoking article.

In one embodiment, the tobacco industry product is a heating devicewhich releases compounds by heating, but not burning, a substratematerial. The material may be for example tobacco or other non-tobaccoproducts, which may or may not contain nicotine. In one embodiment, theheating device is a tobacco heating device.

In one embodiment, the tobacco industry product is a hybrid system togenerate aerosol by heating, but not burning, a combination of substratematerials. The substrate materials may comprise for example solid,liquid or gel which may or may not contain nicotine. In one embodiment,the hybrid system comprises a liquid or gel substrate and a solidsubstrate. The solid substrate may be for example tobacco or othernon-tobacco products, which may or may not contain nicotine. In oneembodiment, the hybrid system comprises a liquid or gel substrate andtobacco.

Filter units described herein can be provided to users as an integralcomponent of a smoking article or as a discrete component separate froma smoking article. When provided separately, filter units and smokingarticles can be packaged separately, or packaged together as a kit ofparts.

Smoking articles such as cigarettes and their formats are often namedaccording to the cigarette length: “regular” (typically in the range68-75 mm, e.g. from about 68 mm to about 72 mm), “short” or “mini” (68mm or less), “king-size” (typically in the range 75-91 mm, e.g. fromabout 79 mm to about 88 mm), “long” or “super-king” (typically in therange 91-105 mm, e.g. from about 94 mm to about 101 mm) and “ultra-long”(typically in the range from about 110 mm to about 121 mm).

They are also named according to the cigarette circumference: “regular”(about 23-25 mm), “wide” (greater than 25 mm), “slim” (about 22-23 mm),“demi-slim” (about 19-22 mm), “super-slim” (about 16-19 mm), and“micro-slim” (less than about 16 mm). Accordingly, a cigarette in aking-size, super-slim format will, for example, have a length of about83 mm and a circumference of about 17 mm. Cigarettes in the regular,king-size format are preferred by many customers, namely with acircumference of from 23 to 25 mm and an overall length of from 75 to 91mm.

Each format may be produced with filters of different lengths, smallerfilters being generally used in formats of smaller lengths andcircumferences. Typically the filter length will be from about 15 mm,associated with short, regular formats, to 30 mm, associated withultra-long super-slim formats. The tipping paper will have a greaterlength than the filter, for example from 3 to 10 mm longer, such thatthe tipping paper covers the filter and overlaps the tobacco rod toconnect the filter to the tobacco rod.

Smoking articles and filter units described herein can be made in, butare not limited to, any of the above formats.

The filter material forming any of the filter units or other filtercomponents described herein can comprise cellulose acetate fibre tow.The filter material can also be formed using other materials used toform fibres, such as polyvinyl alcohol (PVOH), polylactic acid (PLA),polycaprolactone (PCL), poly(1-4 butanediol succinate) (PBS),poly(butylene adipate-co-terephthalate)(PBAT), starch based materials,paper, cotton, aliphatic polyester materials and polysaccharide polymersor a combination thereof. The filter material may be plasticised with asuitable plasticiser for the filter material, such as triacetin wherethe filter material is cellulose acetate tow, or may be non-plasticised.The tow used to produce the filter unit or other filter component canuse any suitable specification, such as fibres having a ‘Y’ shaped orother cross section, filamentary denier values between 2.5 and 15 denierper filament, for example between 3.0 and 9.0 denier per filament andtotal denier values of 10,000 to 50,000, for example between 15,000 and45,000.

As used herein, the terms “flavour” and “flavourant” refer to materialswhich, where local regulations permit, may be used to create a desiredtaste or aroma in a product for adult consumers. They may includeextracts (e.g., liquorice, hydrangea, Japanese white bark magnolia leaf,chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon,herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon,scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery,cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, roseoil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine,ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, ora mint oil from any species of the genus Mentha), flavour enhancers,bitterness receptor site blockers, sensorial receptor site activators orstimulators, sugars and/or sugar substitutes (e.g., sucralose,acesulfame potassium, aspartame, saccharine, cyclamates, lactose,sucrose, glucose, fructose, sorbitol, or mannitol), and other additivesor substances such as charcoal, chlorophyll, minerals, botanicals, orbreath freshening agents. They may be imitation, synthetic or naturalingredients or blends thereof. They may be in any suitable form, forexample, oil, liquid, or powder.

In the figures described herein, like reference numerals are used toillustrate equivalent features, articles or components.

FIG. 1a is a side-on cross sectional view of a first filter unit 1including a tube 2, formed from filter material in the present example,and forming part of a smoking article 3. The smoking article 3 has amouth end 3 a, arranged to be placed in the user's mouth when smoking,and a lit end 3 b, arranged to be lit when smoking. The filter unit 1 isconnected to an aerosol generating material 4, in the present case cuttobacco in the form of a rod, by a tipping paper 5. The aerosolgenerating material 4 is wrapped in a wrapper 6, for instance cigarettepaper.

The tube 2 comprises a wall having inner and outer surfaces which aresubstantially circular in cross section, in the present example, forcross sections taken along the longitudinal length of the tube. An innerdiameter of the tube 2 is defined between two diametrically oppositepoints on the inner surface of the wall, while an outer diameter of thetube 2 is defined between two diametrically opposite points on the outersurface of the wall. The wall of the tube 2 may have a thickness in therange of about 0.5 mm to about 5 mm. For example, the wall may have athickness of between about 1 mm and about 4 mm, between about 1.0 mm andabout 3 mm or between about 1.0 mm and about 2 mm, or about 1.3 mm.

The tube 2 has a first portion 2 a and a second portion 2 b. In FIG. 1,these portions 2 a, 2 b are disposed longitudinally along the length ofthe tube 2. As shown in FIG. 1, the first and second portions 2 a, 2 bare arranged either side of a longitudinal position on the tubeindicated by dashed line ‘X’. The first portion 2 a of the tube 2extends from an end of the tube 2 furthest from the mouth end 3 a of thesmoking article 3 up to the dashed line ‘X’, and the second portion 2 bof the tube 2 extends from the dashed line ‘X’ to the mouth end 3 a ofthe smoking article. An inner diameter of the first portion 2 a of thetube 2 is different from an inner diameter of the second portion 2 b ofthe tube 2. The second portion 2 b is at a distal end of the filterunit, in particular at the mouth end 3 aof the smoking article 3 in thepresent example.

In the present example, an inner diameter of the second portion 2 b,illustrated in FIG. 1 by arrow ‘B’, is greater than an inner diameter ofthe first portion 2 a, illustrated by arrow ‘A’. The inner diameter ‘A’of the first portion 2 a can be in the range of about 2 mm to about 6mm, about 3 mm to about 5 mm, or about 3 mm to about 4 mm. For example,the inner diameter of the first portion 2 a may be about 5 mm. The innerdiameter ‘B’ of the second portion 2 b varies along the length of thesecond portion 2 b in the present example. The largest inner diameter‘B’ of the second portion 2 b can be in the range of about 2.5 mm toabout 8 mm, about 3 mm to about 7 mm, or about 4 mm to about 6 mm. Forexample, the largest inner diameter ‘B’ of the second portion 2 bmay beabout 5 mm.

The overall length of the tube 2 may be in the range of about 3 mm toabout 25 mm, or about 5mm to about 12 mm. For example, the length of thetube 2 may be about 5, 6, 7, 8, 9 or 10 mm.

The length of the first portion 2 a may be in the range of about 2 mm toabout 25 mm, or about 4 mm to about 10 mm. For example, the length ofthe first portion 2 a may be about 4, 5, 6, 7, 8 or 9 mm.

The length of the second portion 2 b may be in the range of about 0.5 mmto 8 mm. For example, the length of the second portion 2 b may be about1 mm to about 5 mm, about 1 mm to about 3 mm or about 2 mm.

The second portion 2 b may be formed by indenting the filter material atthe end of the tube 2 closest to the mouth end 3 a of the smokingarticle. Alternatively, the second portion 2 b may be formed by cuttingthe end of the tube 2 to remove filter material from the end of the tube2.

In the present example, the outer diameter of the second portion 2 b isthe same as the outer diameter of the first portion 2 a.

In the present example, each of the first portion 2 a and the secondportion 2 b has a first end and a second end. The second end of thefirst portion 2 a adjoins the first end of the second portion 2 b, andhas an inner diameter substantially the same as the first end of thesecond portion 2 b.

The tube 2 has a longitudinal axis (not shown). The inner surface of thefirst portion 2 a is substantially parallel to the longitudinal axis ofthe tube 2. The inner surface of the second portion 2 b is chamfered inthat it is at an angle to the longitudinal axis of the tube 2, in thepresent example. The inner diameter of the second portion 2 b decreaseswith distance from a distal end, for instance the mouth end 3 a, of thefilter unit. The angle of intersection between a straight line followingthe inner surface of the second portion 2 b of the tube 2 and thelongitudinal axis of the tube 2 may be in the range of about 10° toabout 80°, or about 20° to about 70°, or about 30° to about 60°. Forexample, the angle may be about 45°.

Although a tube 2 having a uniformly chamfered inner edge has beendescribed with reference to FIG. 1, other tube shapes can be used. Forinstance, the second portion 2 b of the tube 2 can have an innerdiameter ‘B’ which is uniform along the length of the second portion 2b, and therefore forms a step at the location shown by line ‘X’ betweenthe first and second portions 2 a, 2 b. Alternatively or in addition, achamfer or step as described in respect of the inner diameter of thesecond portion 2 b of the tube 2 may be provided in the outer diameterof the second portion 2 b of the tube 2. FIG. 1b illustrates an outerchamfered tube 2′ which can be used in place of the tube 2 used in thesmoking article 3 of FIG. 1a , in which a chamfer is provided on anouter edge of the tube 2′ such that an outer diameter of the secondportion 2 b′, illustrated in FIG. 1b by arrow ‘D’, is smaller than anouter diameter of the first portion 2 a′, illustrated by arrow ‘C’. Thetube 2′ has a longitudinal axis (not shown). The outer surface of thefirst portion 2 a′ is substantially parallel to the longitudinal axis ofthe tube 2′. The outer surface of the second portion 2 b′ is chamferedin that it is at an angle to the longitudinal axis of the tube 2′, inthe present example. The angle of intersection between a straight linefollowing the outer surface of the second portion 2 b′ of the tube 2′and the longitudinal axis of the tube 2′ may be in the range of about10° to about 80°, or about 20° to about 70°, or about 30° to about 60°.For example, the angle may be about 45°.

Referring again to FIG. 1a , in the present example, the first filterunit 1 further includes a sleeve 7. The sleeve 7 is formed from a sheetmaterial such as plug wrap. In alternative examples, the sleeve 7 can beformed in other ways, for instance from plastic or other materials.

The first filter unit 1 also includes an upstream filter segment 8,arranged upstream of the tube 2 in the direction of mainstream smokewhen the smoking article is drawn on by a user. The upstream filtersegment 8 has a longitudinal axis (not shown). The upstream filtersegment 8 has a curved outer surface 8 a circumscribing the segment 8, afirst longitudinal end surface 8 a closest to the lit end 3 a of thesmoking article 3 and a second longitudinal end surface 8 b closest tothe mouth end 3 a of the smoking article 3. The longitudinal endsurfaces 8 a, 8 b are perpendicular to the longitudinal axis of theupstream filter segment 8. In the present example, the tube 2 and theupstream filter segment 8 have a common longitudinal axis.

The sleeve 7 is wrapped around the tube 2 and the upstream filtersegment 8. In the present example, an adhesive is provided between thesleeve 7 and the tube 2 and upstream filter segment 8 and in this waythe sleeve 7 connects the tube 2 to the upstream filter segment 8.

In the present example, the end of the tube 2 closest to the mouth end 3a of the smoking article 3 is flush with the end of the sleeve 7 closestto the mouth end 3 a of the smoking article 3. However, in alternativeexamples, the tube 2 may extend beyond the end of the sleeve 7 closestto the mouth end 3 a of the smoking article 3, or may stop short of theend of the sleeve 7 closest to the mouth end 3 a of the smoking article3. For instance, when the outer chamfered tube 2′ of FIG. 1b is used inplace of the tube 2 of FIG. 1a , the sleeve 7 may surround only thefirst portion 2 a′ of the tube 2′, and the tipping 5 can also extend upto the edge of the sleeve 7 closest to the mouth end 3 a of the smokingarticle 3. In this way, the smoking article 3 can be provided with anouter chamfered edge at the mouth end 3 a giving a smooth surfaceagainst which the users lips can be placed, facilitating the user inholding the smoking article in their mouth. In the present example, thesleeve 7 fully surrounds the outer surface of the upstream filtersegment 8.

The length of the upstream filter segment 8 may be selected according tothe desired filtration performance of the filter unit 1, and may be inthe range 5 mm to 25 mm, or 10 mm to 15 mm. For example, the length ofthe upstream filter segment 8 may be about 12 mm.

The outer diameter of the upstream filter segment 8 may be substantiallythe same as the outer diameter of the tube 2. Either or both of the tube2 and the upstream filter segment may comprise a separate plug wrap (notshown) around which the sleeve 7 is wrapped.

The tube 2 and upstream filter segment 8 may be formed of filtermaterial, in particular a fibrous filter material. The tube 2 and/orupstream filter segment 8 can contain substances such as additives oragents for modifying the aerosol, in the present case smoke, generatedby the smoking article 3. For example, a frangible capsule (not shown)containing a flavourant or other additive or substance such as water maybe located within the upstream filter segment 8. The capsule can belocated at a central longitudinal position within the upstream filtersegment 8, or may be offset from the central longitudinal position.

The capsule has a liquid centre and a frangible outer shell which can bebroken by a user by squeezing the filter unit 1, to thereby release theflavourant. The flavourant is transferred to the aerosol generated bythe smoking article 3 as the smoking article 3 is smoked by the user.

In alternative examples, the first filter unit 1 may include alternativesubstances such as additives or agents for modifying the aerosolgenerated by the smoking article 3, such as granules of activated carbonor other adsorbents, humectants, diluents etc.

The smoking article 3 can be a cigarette in any of the smoking articleformats described herein.

FIG. 1c is a side-on cross sectional view of a filter insert 10 for usewith the filter unit of FIG. 1a . The filter insert 10 includes acylindrical element 11 formed from cellulose acetate tow wrapped in asleeve 12, in the present case a plug wrap. The filter insert 10 may beinserted into the hollow centre of the tube 2 of the smoking article 3by a user, for instance such that the insert 10 abuts the secondlongitudinal end surface 8 b of the upstream filter segment 8. Thefilter insert 10 may include a smoke modifying substance allowing theuser to alter properties of the aerosol passing through the smokingarticle 3 when the smoking article 3 is smoked and the filter insert 10is inserted into the tube 2. The inner chamfer in the second portion 2 bof the tube 2 can facilitate insertion of the filter insert 10 into thetube 2 and, for instance, enable the outer diameter of the filter insert10 to be substantially the same as the inner diameter ‘A’ of the tube 2,which would otherwise make insertion of the insert 10 into the tubedifficult.

FIG. 2 is a side-on cross sectional view of a discrete second filterunit 15 including a tube 16 formed from filter material and provided asa separate unit 15 for use with a smoking article 17. The second filterunit 15 can be attached onto the mouth end 17 a of the smoking article17 by a user. The second filter unit 15 is configured to modify one ormore properties of an aerosol, such as smoke, which is generated by thesmoking article 17. The second filter unit 15 has a mouth end 16 aarranged to be inserted into a user's mouth when the second filter unit15 is attached to the smoking article 17.

The tube 16 of the second filter unit 15 is generally similar in designto the tube 2 of the first filter unit 1 illustrated in FIG. 1a , andcorresponding features and dimensions apply except where alternativelystated below.

The tube 16 has a first portion 16 a and a second portion 15 b. Theseportions 16 a, 16 b are the portions of the tube 16 either side of alongitudinal position on the tube indicated in FIG. 2 by dashed line‘X’. The first portion 16 a of the tube 16 extends from an end of thetube 16 closest to the mouth end 16 a of the second filter unit 15 up tothe dashed line ‘X’, and the second portion 10 of the tube 16 extendsfrom the dashed line ‘X’ to the edge of the tube 16 furthest from themouth end 16 a of the filter unit. An inner diameter of the firstportion 16 a of the tube 16 is different from an inner diameter of thesecond portion 16 b of the tube 16.

In the present example, an inner diameter of the second portion 16 b,illustrated in FIG. 2 by arrow ‘B’, is greater than an inner diameter ofthe first portion 16 a, illustrated by arrow ‘A’. The inner diameter ‘A’of the first portion 16 a may be in the range of about 5 mm to about 10mm, about 6 mm to about 9 mm, or about 6 mm to about 9 mm. For example,the inner diameter of the first portion 16 a may be about 8 mm. Innerdiameter of the first portion may be selected to correspond to the outerdiameter of the mouth end 17 a of the smoking article 17. The innerdiameter ‘B’ of the second portion 10 varies along the length of thesecond portion 10 in the present example. The largest inner diameter ‘B’of the second portion 16 b can be in the range of about 6 mm to about 12mm, about 6 mm to about 10 mm, or about 8 mm to about 10 mm. Forexample, the largest inner diameter ‘B’ of the second portion 2 b may beabout 9 mm.

In the present example, the outer diameter of the second portion 16 b,is the same as the outer diameter of the first portion 16 a.

In the present example, the second filter unit 15 further includes asleeve 18. The sleeve 18 is formed from a sheet material such as plugwrap. In alternative examples, the sleeve 18 can be formed in otherways, for instance from plastic or other materials.

The second filter unit 15 also includes a downstream filter segment 19,arranged downstream of the tube 16 in the direction of mainstream smokewhen the smoking article 17 is drawn on by a user with the second filterunit 15 attached to the smoking article 17. The downstream filtersegment 19 has a longitudinal axis (not shown). The downstream filtersegment 19 has a longitudinal end surface 19 a furthest from the mouthend 16 a of the second filter unit 15. In the present example, the tube16 and the downstream filter segment 19 have a common longitudinal axis.

The sleeve 18 is wrapped around the tube 16 and the downstream filtersegment 19. In the present example, an adhesive is provided between thesleeve 18 and the tube 16 and downstream filter segment 19 and in thisway the sleeve 18 connects the tube 16 to the downstream filter segment19.

In the present example, the end of the tube 16 furthest from the mouthend 16 a of the second filter unit 15 extends beyond the end of thesleeve 18 furthest from the mouth end 16 a of the second filter unit 15.In the present example, the tube 16 extends 0.5 mm beyond the sleeve 18.However, in alternative examples, the tube 16 may extend between about0.5 and 10 mm, for instance between about 0.5 mm and 3 mm beyond the endof the sleeve 18 furthest from the mouth end 16 a of the second filterunit 15, or may be flush with the edge of the sleeve 18 or stop short ofthe end of the sleeve 18 furthest from the mouth end 16 a of the filterelement 15. In the present example, the sleeve 18 fully surrounds theouter surface of the downstream filter segment 19.

The length of the downstream filter segment 19 may be selected accordingto the desired filtration performance of the second filter unit 15, andmay be in the range 5 mm to 25 mm, or 10 mm to 15 mm. For example, thelength of the downstream filter segment 19 may be about 12 mm.

The outer diameter of the downstream filter segment 19 may besubstantially the same as the outer diameter of the tube 16. Either orboth of the tube 16 and the downstream filter segment 19 may comprise aseparate plug wrap (not shown) around which the sleeve 18 is wrapped.

The tube 16 and downstream segment 19 may be formed of filter material,in particular a fibrous filter material, as described herein. The tube16 and/or downstream segment 19 can contain substances such as additivesor agents for modifying the aerosol, in the present case smoke,generated by the smoking article 17. For example, a frangible capsule(not shown) as described elsewhere herein and containing a flavourant orother additive may be located within the downstream filter segment 19.The capsule can be located at a central longitudinal position within thedownstream filter segment 19, or may be offset from the centrallongitudinal position.

In alternative examples, the second filter unit 15 may includealternative substances such as additives or agents for modifying theaerosol generated by the smoking article 17, such as granules ofactivated carbon or other adsorbents, humectants, diluents etc.

The smoking article 17 can be a conventional cigarette in any of thesmoking article formats described herein.

The discrete second filter unit 15 can be coupled or attached to thesmoking article 17 by a user. In the present example, the tube 16 of thesecond filter unit 15 is arranged to receive a mouth end portion 17 a ofthe smoking article 17 so that the second filter unit 15 and the smokingarticle 17 can be attached or coupled together by a user. The mouth end17 a of the smoking article 17, in the present example, abuts thelongitudinal end surface 19 a when the second filter unit 15 isconnected to the smoking article 17. The user can select whether or notto attach the second filter unit 15 to the smoking article 17 prior tosmoking the smoking article 17, and can in this way control the lengthof filter of the smoking article 17 and therefore the level offiltration of the aerosol generated by the smoking article 17, as wellas any other modification of the aerosol performed by the second filterunit 15.

The second filter unit 15 may be attached to the smoking article 17 inany suitable way. This may include forming an interference fit betweenan inner surface of the tube 16 and an outer surface of the smokingarticle 17. In this case, the interference fit is such that a seal isformed at the interface between the inner surface of the tube 16 and theouter surface of the smoking article 17, which inhibits the ingress ofgases (such as air) that would normally enter into the smoking article17 via a gap between the outer surface of the smoking article 17 and theinner surface of the tube 16. The amount of air entering into a smokingarticle between the two neighbouring surfaces may be variable and/orunwanted. Restricting the ingress of air therefore provides a degree ofcontrol of the airflow into and/or through the smoking article 17.

The tube 16 has a longitudinal axis (not shown). The inner surface ofthe first portion 16 a is substantially parallel to the longitudinalaxis of the tube 16. The inner surface of the second portion 16 b ischamfered in that it is at an angle to the longitudinal axis of the tube16, in the present example. The angle of intersection between a straightline following the inner surface of the second portion 16 b of the tube16 and the longitudinal axis of the tube 16 may be in the range of about10° to about 80°, or about 20° to about 70°, or about 30° to about 60°.For example, the angle may be about 45°.

In the present example, the inner portion of the edge of the tube 16furthest from the mouth end 16 a of the second filter unit 16 ischamfered such that an inner diameter of the second portion 16 b,illustrated by arrow ‘B’ is greater than an inner diameter of the firstportion 16 a, illustrated by arrow ‘A’. This arrangement makes it easierfor the user to insert an end 17 a of the smoking article 17 into thetube 16, in order to couple the second filter unit 15 to the smokingarticle 17.

FIG. 3a is a side-on cross sectional view of a third filter unit 20forming part of a smoking article 21. The third filter unit 20 comprisesa body 22 formed of filter material. The smoking article 21 includes arod of aerosol generating material 23, in the present case cut tobacco,wrapped in a sheet material 24, in the present case cigarette paper. Therod 23 and third filter unit 20 are connected by tipping 25 whichsurrounds the third filter unit 20 and partially surrounds the rod 23.The smoking article 21 has a mouth end 21 a to be inserted in the user'smouth when smoking. The body 22 of the third filter unit 20 has an endsurface 26 at the end of the body 22 closest to the mouth end 21 a ofthe smoking article 21 furthest from the rod 23 and a recess 27 formedin the end surface 26. The recess 27 is a hollow depression in the body22. The recess 27 extends into, but not entirely through, the body 22.In the present example, the body 22 is cylindrical, and the end surface26 is a longitudinal end surface of the body 22.

In the present example, the recess 27 has the shape of a conicalfrustum, and has an inner base surface 27 a and an inner side surface 27b. In other examples, the recess 27 may have the shape of otherfrustums, and may have multiple side surfaces. Alternatively, the recessmay be cylindrical, conical or hemispherical in shape.

The recess 27 may be formed in the filter material of the body 22 byindentation. In this case, the filter material of the body 22 may becompressed during formation of the recess 27. In other words, the filtermaterial at or close to an inner surface of the recess 27 is denser thanthe filter material in other areas of the body 22, such as the end ofthe body 22 furthest from the longitudinal end surface 26.Alternatively, the recess 27 can be formed by removing filter materialfrom the body 22 at the end surface 26. The recess 27 can direct smoketo a particular portion of the body 22 in which the recess 27 islocated, by reducing the volume of material in that part of the body 22,and enable particular formations of smoke from the mouth end 21 a of thesmoking article 21.

The body 22 may include a smoke modifying substance/additive (not shown)disposed within the filter material of the body 22. The smoke modifyingsubstance/additive may be any smoke modifying substance/additive, suchas flavours or other additives, as described herein.

The third filter unit 20 may further include a sleeve 28, such as plugwrap, which is wrapped around the body 22. In the present example, thebody 22 is flush at the mouth end 21 a of the smoking article with theedge of the sleeve 28. In other examples, the sleeve 28 and/or tipping25 may extend beyond an end of the body 22. The space thus formed by thesleeve 28 and/or tipping 25 extending beyond an end of the body 22, suchas the longitudinal end surface 26, may be arranged to receive a filterinsert, such as that illustrated in FIG. 1 c.

FIG. 3b is an end-on view of the third filter unit 20. FIG. 3c is anend-on view of another design for a third filter unit 20′, in this casehaving a triangular shaped recess having an inner base surface 27 a′ andinner side surfaces 27 b′ and longitudinal end surface 26′. FIG. 3d isan end-on view of another design for a third filter unit 20″, in thiscase having a hexagonal shaped recess having an inner base surface 27 a″and inner side surfaces 27 b″ and longitudinal end surface 26″.

The third filter units 20, 20′, 20″ described herein having a recessformed in an end surface can be used to form components of other filterunits and filter inserts described herein. For instance, the thirdfilter units 20, 20′, 20″ described herein having a recess formed in anend surface can be used as the upstream filter segment 8 of the firstfilter unit 1 described with reference to FIG. 1a , as the filter insert10 as described with reference to FIG. 1c , or as the downstream filtersegment 19 of the second filter unit 15 described with reference to FIG.2. In each case, the recess would be arranged to face the mouth end ofthe product.

FIG. 4 is a side-on cross sectional view of a fourth filter unit 30,including a tube 31 formed from sheet material, and provided as adiscrete component for use with a separate smoking article 17 asdescribed with reference to FIG. 2. The fourth filter unit 30 has amouth end 30 a and comprises a tube 31 having a first portion 31 a and asecond portion 31 b. An inner diameter of the first portion 31 a isdifferent from an inner diameter of the second portion 31 b. The fourthfilter unit 30 also includes a downstream filter plug 32 arranged closerto the mouth end 30 a of the filter unit 30 than the tube 31 and formedfrom filter material. The fourth filter unit 30 further comprises asleeve 33 partially surrounding the tube 31 and surrounding thedownstream filter plug 32. The tube 31 of the present example can beformed from a sheet material such as paper, card, cardboard, plastic orsimilar materials.

The fourth filter unit 30 can be coupled or attached to another tobaccoindustry product, such as smoking article 17, by a user. The tube 31 isarranged to receive a portion of the smoking article 17, for instancethe mouth end 17 a of the smoking article 17, so that the filter unit 30and the smoking article 17 can be attached or coupled together by auser. The fourth filter unit 30 is configured to modify one or moreproperties of an aerosol, such as smoke, which is generated by thesmoking article 17.

In the present example, the tube 31 is formed from a sheet materialseparate from the sleeve 33, enabling the tube 31 to be formed ofstiffer material than may be possible for use in wrapping the downstreamfilter plug 32. An inner diameter ‘B’ of the second portion 31 b isgreater than an inner diameter ‘A’ of the first portion 31 a. Thisarrangement makes it easier for the user to couple the fourth filterunit 30 to the smoking article 17. In the present example, an outerdiameter ‘B’ of the second portion 31 b is greater than an outerdiameter of the first portion 31 a. This arrangement may be referred toas the tube 31 having a ‘widened end’. The dimensions of the tube 31 ofFIG. 4 can correspond to the dimensions of the tube 16 described withreference to FIG. 2.

The tube 31 formed from sheet material described with reference to FIG.4 can be used in place of the tube 2 at the mouth end of the smokingarticle 3 described with reference to FIG. 1 a.

FIGS. 5a to 5d are perspective views of an apparatus 40 for shaping atobacco industry product 41. The tobacco industry product 41 may be (forexample) a smoking article, a filter, or a tube, or other componentsdescribed herein. The filter may be an individual filter unit, or may bepart of a smoking article. The tube may be part of another tobaccoindustry product, e.g. a filter unit or a smoking article. Any of thesetobacco industry products 41 may have a longitudinal axis. Any of thesetobacco industry products may have a longitudinal end surface. Tubularcomponents may also have an inner surface around the inside of the tube.The apparatus 40 can be used, for instance, to form any of the tubes 2,2′, 16, 31 of the first, second and fourth filter units 1, 15, 30described herein, or the recess 27 formed in the filter body 22 of thethird filter unit 20 described herein.

Referring to FIG. 5a , the apparatus 40 comprises a shaping head 42configured to change the shape of a first end of the tobacco industryproduct 41 (not shown in this Figure). The apparatus 40 furthercomprises an actuator arrangement 43 configured to move the shaping head42 and/or tobacco industry product 41. The actuator arrangement 43 isconfigured to move the shaping head 42 and/or tobacco industry product41 in a direction substantially parallel to a longitudinal axis of thetobacco industry product 41 such that the shaping head 42 is broughtinto contact with a first end 41 a of the tobacco industry product 42 inorder to change the shape of the first end 41 a.

Alternatively or in addition to the above, the actuator arrangement 43can be configured to move the shaping head 42 and/or tobacco industryproduct 41 such that the shaping head 42 is brought into contact with afirst longitudinal end surface and/or an inner surface of the tobaccoindustry product 42 in order to change the shape of the firstlongitudinal end surface and/or an inner surface.

In some examples, a receiving unit is arranged to receive and grip thetobacco industry product 41, so as to hold tobacco industry product 41in position while it is shaped. This may be achieved by mechanicalmeans, such as a clamp, or alternatively by means such as vacuumsuction, as described in more detail below.

In use, when the shaping head 42 is brought into contact with the firstend 41 a of the tobacco industry product 41, the pressure exerted on theend 41 a of the tobacco industry product 41 by the shaping head 42deforms the material of the tobacco industry product 41, therebychanging a shape of the end of the tobacco industry product 41. Changingthe shape of the end of the tobacco industry product 41 may, forinstance, include changing an inner and/or outer diameter of the tobaccoindustry product 41, as well as forming an indentation in the end 41 a.

The actuator arrangement 43 may be configured to move the shaping head42 and/or tobacco industry product 41 in a reciprocating fashion. Inother words, actuator arrangement 43 may be configured to move theshaping head 42 and/or tobacco industry product 41 so that they arefirst brought into contact with each other and are then moved apart fromeach other.

The shaping head 42 may be cylindrical in shape. In the present example,the shaping head 42 is substantially cylindrical in shape, and the endof the shaping head 42 has a chamfered profile. In other words, theshaping head 42 comprises a surface which is angled with respect to aside surface and a longitudinal end surface thereof.

In other exemplary arrangements, the shaping head 42 may be conical inshape. The shaping head 42 may have the shape of a frustum, such as aconical frustum. The shaping head 42 may be hemispherical in shape ormay have a shape which has relatively low orders of rotational symmetryor no rotational symmetry. For instance, when forming the third filterunits 20′ and 20″ of FIGS. 3c and 3d herein, the end of the shaping head42 would have a triangular frustum shape with order 3 rotationalsymmetry or a hexagonal frustum shape with order 6 rotational symmetry.The shaping head 42 can have, for instance, order 1, 2, 3, 4, 5, 6, 7, 8or infinite/continuous rotational symmetry.

In the present example, the shaping head 42 has a longitudinal axis (notshown). The apparatus 40 is configured to rotate the shaping head 42about its longitudinal axis, for instance for shaping heads 42 havinginfinite/continuous rotational symmetry. Rotating the shaping head 42when the shaping head 42 is brought into contact with the end of thetobacco industry product 41 can provide a more even change in the shapeof the end of the tobacco industry product 41, resulting in a uniformend profile, compared to a fixed shaping head 42. However, the apparatus40 can be configured such that the shaping head 42 is fixed when theshaping head 42 has an order of symmetry less than infinite, forinstance order 1, 2, 3, 4, 5, 6, 7, 8 rotational symmetry. A knownmethod of applying a shape to a filter which is visible from the mouthend of the filter is to create a tube filter having that shape runningthrough the centre as a bore. However, in such cases, the standardcigarette making process requires such a shape to have at least order 2rotational symmetry, otherwise the shape will not be the same when thetube is used in different orientations. The use of a shaping head 42which can be applied directly to a filter body addresses this issue,meaning that shapes with order 1 rotational symmetry can be applieduniformly to cigarette filters.

FIGS. 6a to 6 c are side-on cross sectional and end-on views ofrespective first, second and third shaping heads 42, 42′ and 42″ for usewith the apparatus of FIGS. 5a to 5d . The first shaping head 42,illustrated in FIG. 6a , comprises a conical frustum shape, and can beused to form the third filter unit 20 of FIGS. 3a and 3b . The secondshaping head 42′, illustrated in FIG. 6b , comprises a triangularfrustum shape, and can be used to form the third filter unit 20′ of FIG.3c . The third shaping head 42″, illustrated in FIG. 6c , comprises ahexagonal frustum shape, and can be used to form the third filter unit20″ of FIG. 3 d.

The apparatus 40 may be configured so that, in use, the longitudinalaxis of the shaping head 42 and the longitudinal axis of the tobaccoindustry product 41 are aligned. In such an arrangement, the shapinghead 42 and the tobacco industry product 41 may be said to have a commonlongitudinal axis.

In the present example, the apparatus 40 comprises a drum 43 arranged tomove the tobacco industry product 41 relative to the shaping head 42 inorder to bring the shaping head 42 into contact with an end of thetobacco industry product 41.

The drum 43, in the present example, is provided as a modification tothe known separator drum used in cigarette manufacture to separate firstand second tobacco rods so that a filter can be placed between thetobacco rods and the rods and filter can then be wrapped in tippingpaper. The drum 43 is modified to include a head support unit 44 whichsupports a plurality of shaping heads 42 arranged such that they arespaced circumferentially around the drum 43. The longitudinal axis ofeach of the shaping heads 42 is parallel to the axis of rotation of thedrum 43. The drum 43 includes a plurality of moving plates 45 in each ofwhich first and second product receiving units or regions 46 areprovided, in the form of flutes 46 in the present example. Each flute 46is arranged to receive a tobacco industry product 41 and is generallyshaped as an elongate groove formed in the plate 45 within which thetobacco industry product 41 can sit. The tobacco industry products 41are held within the flutes 46 by suction through apertures formed in thebase of the flutes 46, as known in conventional separator and similardrums.

In the present example, the moving plates 45 move in a reciprocatingmanner towards and away from the shaping heads 42 held by the headsupport member 44 in order to bring tobacco industry products 41 intocontact with the shaping heads 42. In an alternative exemplaryarrangement, the apparatus 40 may be configured so that both the plates45 and the head support unit 44 are arranged to move in use, or so thatonly the head support unit 44 moves, in order to bring the shaping heads42 into contact with the end of the tobacco industry product 41. Shouldadditional force be required to hold the tobacco industry products 41within the product receiving regions 46 provided in the plates 45, thenthese can be adapted to include an alternative gripping arrangement.Alternatively or additionally, a swash-plate type arrangement can beused to push tobacco industry products 41 longitudinally from the endopposite to the end which is to be shaped.

The apparatus 41 may further comprise a heating element 47 which isarranged to heat the shaping heads 42. When the shaping heads 42 areheated during contact with the end of the tobacco industry product 41,the heat may deform the material of the tobacco industry product 41,which aids in changing the shape of the end of the tobacco industryproduct 41. The heating element may be an induction coil. Alternatively,the shaping head 42 may be heated by a hot air system or a directthermocouple.

As shown in FIG. 5d , a gearing mechanism 48 can be used to rotate theshaping heads 42, in the form of mandrels in the present example. Eachmandrel 42 extends into a base shaft 42 a which extends into and issupported by the head support unit 44. In particular, the head supportunit 44 includes first and second bearings 44 a, 44 b which support thebase shaft 42 a of each mandrel 42, allowing it to rotate. Each mandrelbase shaft 42 a is also connected to and arranged to be turned via amandrel driving cog 48 a which in turn meshes with a fixed cog 48 bextending around the periphery of the drum 43 and fixed in relation tothe head support unit 44. As the outer portions of the drum 43 rotate,including the head support unit 44, this causes the mandrel driving cog48 a for each mandrel 42 to rotate as its teeth mesh with the fixed cog48 b, and this rotates the mandrel 42. Other arrangements for turningthe shaping heads 42 can also be used, such as a separate motorarrangement for rotating one or more of the heads 42. The mandreldriving cogs 48 a can be removed from the mandrel base shafts 42 a ofthe mandrels 42 in order to provide fixed rather than rotating mandrels42.

In an alternative exemplary arrangement, the apparatus 40 may furthercomprise a second shaping head (not shown) which is substantially thesame as the shaping head 42 described above, and is arranged to changethe shape of a second end of the tobacco industry product 41. In thisarrangement, the apparatus 40 can shape both ends of the tobaccoindustry product 900, either simultaneously or in sequence.

Also presented herein is a method of shaping a tobacco industry product.The method is shown in FIG. 7 and comprises the steps of: providing atobacco industry product (S101); and changing the shape of a first endof the tobacco industry product by moving a shaping head and/or thetobacco industry product in a direction substantially parallel to alongitudinal axis of the tobacco industry product such that the shapinghead is brought into contact with the first end of the tobacco industryproduct (S102).

Also presented herein is a further method of shaping a tobacco industryproduct. The method is shown in FIG. 8 and comprises the steps of:providing the tobacco industry product (S201); and changing the shape ofa first end of the tobacco industry product by moving a shaping headand/or the tobacco industry product such that the shaping head isbrought into contact with a first longitudinal end surface and/or aninner surface of the tobacco industry product (S202).

In order to address various issues and advance the art, the entirety ofthis disclosure shows by way of illustration various embodiments inwhich the claimed invention(s) may be practiced and provide for superiorsmoking articles and filter units therefor. The advantages and featuresof the disclosure are of a representative sample of embodiments only,and are not exhaustive and/or exclusive. They are presented only toassist in understanding and teach the claimed features. It is to beunderstood that advantages, embodiments, examples, functions, features,structures, and/or other aspects of the disclosure are not to beconsidered limitations on the disclosure as defined by the claims orlimitations on equivalents to the claims, and that other embodiments maybe utilised and modifications may be made without departing from thescope and/or spirit of the disclosure. Various embodiments may suitablycomprise, consist of, or consist essentially of, various combinations ofthe disclosed elements, components, features, parts, steps, means, etc.In addition, the disclosure includes other inventions not presentlyclaimed, but which may be claimed in future.

1. A filter unit for a smoking article comprising: a tube having a firstportion and a second portion, wherein an inner diameter of the firstportion is different from an inner diameter of the second portion; and asleeve at least partially surrounding the tube.
 2. A filter unitaccording to claim 1, wherein the second portion is at a distal end ofthe filter unit.
 3. A filter unit according to claim 2, wherein theinner diameter of the second portion decreases with distance from thedistal end of the filter unit.
 4. A filter unit according to claim 1, 2or 3, wherein an inner diameter of the second portion is greater than aninner diameter of the first portion.
 5. A filter unit according to anyone of claims 1 to 4, wherein an outer diameter of the second portion isgreater than an outer diameter of the first portion.
 6. A filter unitaccording to any one of claims 1 to 4, wherein an outer diameter of thefirst portion is substantially the same as an outer diameter of thesecond portion.
 7. A filter unit according to any one of claims 1 to 6,wherein each of the first portion and the second portion has a first endand a second end, and the second end of the first portion adjoins thefirst end of the second portion and has an inner diameter substantiallythe same as the first end of the second portion.
 8. A filter unitaccording to any one of claims 1 to 7, wherein the tube is formed frompaper, card, cardboard or plastic.
 9. A filter unit according to any oneof claims 1 to 8, comprising: a cylindrical element, wherein the sleeveat least partially surrounds the cylindrical element.
 10. A filter unitaccording to any one of claims 1 to 9, wherein the cylindrical elementis formed from filter material and comprises a body having an endsurface adjacent to the tube and a recess formed in the end surface. 11.A filter unit according to any one of claims 1 to 10, wherein theelement comprises a smoke modifying substance disposed within the filtermaterial of the element.
 12. A filter unit according to claim ii,wherein the smoke modifying substance comprises an encapsulatedsubstance.
 13. A filter unit according to any one of claims 1 to 12,wherein the filter unit is arranged to be coupled to a smoking articleby a user.
 14. A smoking article comprising a filter unit according toany one of claims 1 to
 13. 15. A smoking article according to claim 14,wherein the second portion of the tube is disposed at a mouth end of thesmoking article.
 16. A kit comprising a smoking article and a filterunit according to any one of claims 1 to 13.